1. Field of the Invention
The invention relates to a semiconductor device and an arithmetic and logic unit, a signal converter and a signal processing system using it, and more particularly, to a semiconductor device which can perform parallel arithmetic and, for example, an arithmetic and logic unit which can perform correlation operation, a signal converter which can analog-to-digital or digital-to-analog convert signals and a signal processing system using it.
2. Related Background Art
Conventionally the semiconductor device which performs parallel processing has a problem that, as the number of signals to be parallelly operated increases, the circuit scale increases serially, which increases the manufacturing cost and decreases the yield. Also it has another problem that, due to an increase in the delay in wiring, etc. and an increase in the number of operations in the circuit which an increase in the circuit scale entails, the processing speed falls as well as that power consumption increases significantly.
In the solid-state image sensor shown in FIG. 1, for example, the image pickup element 41 is arranged along the vertical and horizontal axes and the time-series analog signal from the sensing unit 60 as an area sensor is converted into a digital signal by the analog-to-digital converter 40 and is stored once in the frame memory 39. These signals are processed by the arithmetic and logic circuit 38 and are output from the arithmetic and logic output circuit 50. In concrete terms, it is possible to output an object's movement (.DELTA.X, .DELTA.Y), etc. by correlation operation of pieces of data at different times.
When processing a dynamic image real time, however, there is a problem that, due to the number of processes of the operation processing being very large, the circuit scale increases serially for obtaining a more real image, which decreases the processing speed. For example, a device which can really process the MPEG2 system, being proposed as a dynamic image compression/decompression system, is still under development. In the parallel processing, therefore, there are problems of a decrease in the processing speed due to an increase in the circuit scale and an increase in power consumption. Also they entail problems of an increase in the manufacturing cost and a decrease in the manufacturing yield due to an increase in the circuit scale.
Moreover, the majority logic circuit, which is useful for the operation processing circuit, has been treated in the article "An Economical Majority Logic IC Materialized by the CMOS", which appeared on pages 132 to 144 of the Nov. 5, 1973 issue of "Nikkei Electronics". In that case, however, a majority logic circuit is presented as one of the digital signal processes and, in addition, it is formed by the CMOS. So the number of elements by the CMOS as well as the number of operation processing steps increases. It still has similar problems, therefore, that the circuit scale and power consumption increase and that, additionally, the processing speed falls.